Many structures, circuits and other apparatuses benefit from temperature control. For many applications, sunlight is desirably provided to and/or used (e.g., in a solar cell). In addition, the color of an object under sunlight may be determined by the object's absorption spectrum over solar wavelengths. However, this absorption of sunlight in turn will cause the object to heat up to temperatures substantially above ambient air temperatures. For instance, solar cells heat up under sunlight. The resulting increased temperature of the solar cell has adverse consequences on both its efficiency and its reliability. Accordingly, illuminating an object with sunlight or otherwise can result in undesirably high temperatures.
These and other matters have presented challenges to both the illumination of objects and temperature control thereof, for a variety of applications.